A model may fill only visible, unwired parameters
The rule
- Where a node is offered to an agent node as a callable tool, a parameter is fillable by the model when it is connectable and exposed and no data edge already feeds that port.
- A hidden parameter, a non-connectable one, and one a wire already supplies are all outside the model's reach.
What it means
A parameter reaches the model only when three things hold at once: connectable, exposed, and not already fed by a wire. Missing any one pins it — the model cannot fill it, and it does not even appear in the schema offered to the model. The wire check is independent of the other two: a wired parameter is withheld because a wire's value is deterministic run state, and the model must not compete with it, whether or not that same parameter would otherwise be exposed. A parameter the workflow hides is withheld the same way, whether the hiding comes from an explicit instance override or from the node type's own default exposure.
Example
A node offers four parameters as a callable tool: two connectable and exposed by default, one not connectable, and one internal.
["query", "url"]["query"]The non-connectable and internal parameters never appear in either list — being wired or hidden was never the reason they were excluded.